Research summary: Recent research rooted in the resource‐based view of the firm suggests that resources are more likely to create value if they are effectively managed. An underlying assumption of the literature is that firms manage their resources on their own. However, many firms hire consultants to help them do so. In this study, I develop and test hypotheses regarding the impact of technical consultants on the quality of their clients' products. Using data from the Bordeaux wine industry, I find evidence that the use of technical consultants has a positive impact on relative product quality and a negative impact on the extremeness of relative product quality. Moreover, the positive impact of technical consultants on relative product quality is stronger at lower levels of relative resource quality. Managerial summary: Findings from a study in the Bordeaux wine industry indicate that the decision to hire consultants should depend on a firm's strategy. If a firm wants to improve its performance, it should hire consultants. Indeed, the “best practices” of technical consultants are generally more valuable than internally generated knowledge. If a firm wants to achieve outstanding performance, hiring consultants may not be the right decision. Because the “best practices” of technical consultants have more certain performance implications than internally generated knowledge, they decrease the likelihood of extremely low performance. However, their lack of uniqueness also decreases the likelihood of extremely high performance. Finally, the decision to hire consultants should depend on the quality of a firm's resources. Firms with low‐quality resources tend to benefit more from the “best practices” of technical consultants. Copyright © 2016 John Wiley & Sons, Ltd.